Antihypertensive and neuroprotective activities of rhynchophylline: The role of rhynchophylline in neurotransmission and ion channel activity

Ethnopharmacological relevanceUncaria species (Gouteng in Chinese) have been used as ethnopharmacological medicines to treat ailments of the cardiovascular and central nervous systems. As the main alkaloid constituent of Uncaria species, rhynchophylline has drawn extensive attention in recent years for its antihypertensive and neuroprotective activities, and its pharmacological effects are related to ethnopharmacological medicine properties of Uncaria species.Aim of the reviewThis review examined the pharmacological studies and mechanisms of rhynchophylline, with an emphasis on cardiovascular and central nervous system diseases linked to the ethnopharmacological uses of Uncaria species.MethodsWe conducted both an electronic search and a library search of in vivo and in vitro studies. The terms and keywords for the search included rhynchophylline, Uncaria species, Gouteng, pharmacological effects, and mechanism. We focused on the papers, including ours, with studies on all related pharmacological effects and mechanisms of rhynchophylline.ResultsRhynchophylline was the main constituent of several components identified from Uncaria species. Rhynchophylline mainly acts on cardiovascular and central nervous system diseases, including hypertension, bradycardia, arrhythmia, sedation, vascular dementia, epileptic seizures, drug addiction, and cerebral ischemia. Rhynchophylline also has effects on anticoagulation, inhibits vascular smooth muscle cell proliferation, and has been shown to be anti-endotoxemic. The active mechanisms are related to modulation of calcium and potassium ion channels, protection of neural and neuroglial cells, and regulation of central neurotransmitter transport and metabolism. More studies are necessary to verify the pharmacological activities and determine the exact mechanisms of rhynchophylline activity.ConclusionsRhynchophylline treatment of cardiovascular and central nervous system diseases has a strong linkage with traditional concepts and uses of Uncaria species in ethnopharmacological medicine, such as treatment for lightheadedness, convulsions, numbness, and hypertension. As a candidate drug for several cardiovascular and central nervous system diseases, rhynchophylline will attract scientists to pursue the potential pharmacological effects and mechanisms with new technologies. Relatively few clinically relevant studies of rhynchophylline have been conducted. Thus, more in vivo validations and investigations of antihypertensive and neuroprotective mechanisms of rhynchophylline are necessary.

The treatment of cardiovascular and central nervous system diseases with rhynchophylline, the main alkaloid constituent of Uncaria species, has a strong linkage with the traditional concepts and uses of Uncaria species in ethnopharmacological medicine (e.g., lightheadedness, convulsions, numbness, and hypertension). The active mechanisms of rhynchophylline are related to modulation of calcium and potassium ion channels, protection of neural and neuroglial cells, and regulation of central neurotransmitter transport and metabolism. There are relatively few clinical applications of rhynchophylline as a therapeutic agent for cardiovascular and central nervous system diseases, and more in vivo validations and further investigations of its antihypertensive and neuroprotective mechanisms are necessary.Figure optionsDownload as PowerPoint slide